Array a Group of objects?
This answer was inspired by this answer here 

here is a solution that actually allows use to use the array modifier to duplicate grouped objects. It does, however, require one extra mesh.

We begin with our grouped object:



Then add a plane. Go into the object properties for that plane, and enter the instancing tab (called duplication in 2.7). Select faces.



Finally, select your group object then your plane, and hit Ctrl-P to parent them, selecting Object.



Now, finally, if you add an array modifier to your plane, the group object will be duplicated:



Demo file to see final result: